1. Field of the Invention
The invention relates to a printer requiring recording paper replenishment, and relates particularly to a printer comprising a release lever for opening the recording paper path and to a control method for such printer.
2. Description of the Related Art
In printers in which the gap between the print head and platen is narrow, the recording paper can easily be caught between the print head and platen when loading the recording paper. A release lever is typically provided to prevent this by increasing the distance between the print head and platen when the recording paper is loaded, thereby making it easier to insert the recording paper.
In line thermal printers, in particular, the print head touches the platen, thus effectively closing the recording paper path in this area and making it difficult to feed the recording paper between the print head and platen. It is therefore necessary to separate the print head from the platen, thereby opening the recording paper path, before inserting the recording paper.
FIG. 6 shows the mechanism of a line thermal printer. In the mechanism shown in FIG. 6 the release lever 2 operates in conjunction with the print head 6. During printing, print head 6 is pressed against platen 4 with the recording paper disposed therebetween by means of a coil spring or other energized means. This assures tight contact between the recording paper and print head 6, and enables the effective transfer of heat from the print elements in print head 6 to the recording paper.
When recording paper must be loaded, release lever 2 is operated to lift print head 6 from platen 4, thereby forming a gap through which the recording paper can be passed. Note that this operation is referred to below as "opening" the release lever. The recording paper is then inserted through the gap between platen 4 and paper feed roller 5, which is embedded in paper guide 9, and paper feed knob 3 linked to platen 4 is manually turned to advance the recording paper caught between platen 4 and paper feed roller 5. To thus load the recording paper it is necessary for the operator to hold and insert the paper with one hand while turning paper feed knob 3 with the other hand. After advancing the recording paper the required distance, release lever 2 is again operated to close the gap between print head 6 and platen 4 and complete the recording paper loading process. Note that this last operation of release lever 2 to close the gap is also referred to below as "closing" the release lever.
Printers such as described above have become a widely used peripheral device connected to personal computers (PC) and other information processing devices, and people that have never before operated such printers are increasingly exposed to the need and opportunity to use such printers. This widespread use of printers has increased demand for greater ease of use, particularly in the frequently performed, trouble-prone procedure used to load recording paper. Recording paper is one of the most common printer consumables, and the roll paper used in printers that are used in point-of-sale (POS) and electronic cash register (ECR) stations must be replaced right at the checkout counter. Because the recording paper must often be replenished, i.e. installed, while customers are waiting, it is necessary to complete the installation quickly and reliably in order to minimize the customer waiting time.
The conventional method of installing recording paper as described above is, however, both complicated and time-consuming. It is not intuitively understood that paper feed knob 3, shown in FIG. 6, must be turned while inserting the paper. It is therefore necessary to educate and train workers to properly install the recording paper.
It can also be difficult to hold and insert the recording paper with one hand, making sure the paper stays straight, while turning the paper feed knob with the other hand to advance the paper.